ABSTRACT
Man is a slow-breeding animal and, therefore, human mortality was always at a far lower level than in most other animals. There is no reason to suppose that crude birth rates in any large population consistently exceeded about 50 per 1000. An expectation of life at birth of 20 years represents a drastically more severe mortality regime than that experienced today when expectation of life at birth is about 75 years in advanced communities, but even so it is possible to exaggerate the uncertainty of life in such circumstances. Crude birth and death rates were therefore up to 10 per 1000 per annum apart in the period. The opposite side of the coin, of course, is that there were many rural areas where mortality levels were substantially better than those that result from a generalised calculation relating to the country as a whole.
